Pitman connection.



No. 684,435. Patented 0st. I5, |90I. E. A. JDHNSTON.

PITMAN CONNECTION.

(Application filed Dec. 22, 1900.)

(Nu Model.)

.9 i94- WITNESSES: a

UNITED STATES PATENT OFFICE.

EDWARD A. JOHNSTON, OF CHICAGO, ILLINOIS.

PITNIAN CONNECTION.

SEECIFICATION forming part of Letters Patent No. 684,435, dated October15, 1901.

Application filed December 22, 1900. Serial No. 40,750. (No model.)

To @ZZ whom it may concern:

Beit known that I, EDWARD A. JOHNSTON, a citizen of the United States,residing at Chicago, county of Cook, and State of Illinois, haveinvented certain new and useful Improvements in Pitman Connections; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

My invention relates to improvements in pitman connections, and pertainsmore particularly to joints for use in connection with the knife-headsof mowing-machines, although it is equally well adapted for use invarious ot-her relations where a flexible connection between movingparts is desired.

The object of my invention is to provide a ball-and-socket connectionbetween lthe pitman and the reciprocating part wherein the pivotedspoons are held in close and adjustable engagement with the ball bymeans of a spring-actuated link pivoted to one spoon and engaging a camon the other spoon, whereby a simple, durable, and effective joint issecured.

My invention is illustrated in the accompanying drawings, in which-Figure 1 is a plan view of my improved pitman connection as applied tothe knifehead of a mowing-machine. Fig. 2 is a side elevation of thesame. Fig. 3 is a plan view showing the connection in a position to belocked to the cooperating ball on the knifehead. Fig. et is an enlargeddetail view of the pivoted spoon. Fig. 5 is a corresponding view of thefixed spoon, showing the manner of mounting the locking-link; and Fig. 6is an enlarged detail view illustrating the cooperating engagement ofthe link and the respective spoons.

Heretofore it has been customary to secure a ball-and-socket connectionbetween the pitman and the knife-head ofa mowing-machine by means of abolt passing through the spoons, which were brought to bear upon theball by means of a n ut or cam-lever on the bolt. The objection to thissecuring means lies in the fact that the bearing could not be adjustedat all, or, if adjustable, a careless or ignorant operator would makethe bearing between the ball and the spoons either too tight or tooloose. The danger of breakage in a tight connection is manifest, and ifthe connection be too loose the engaging parts will soon pound to piecesunder the rapid heavy shocks incident to machines of this type. Thevalue of the ball-and-socket connection at the knife-head is dependentupon the connection being kept at just the right degree of tightness,and it is characteristic of my invention that this and other desirablefeatures are attained by a spring-actuated locking-link carried by onespoon and having a slidingadjustment with acam on the other link,whereby all wear between the ball and the spoons is automaticallycompensated for.

Referring to the drawings, A represents the pitman-rod of amowing-machine, to which is rigidly attached a spoon a by means of boltspassing through suitable straps formed with said spoon and lying oneither side of the pitman. Beyond these straps the spoon a is providedwith side walls, to which is pivoted, by means of pintle 0.4, thecooperating spoon a', which is adapted to swing toward and from thefixed spoon, as indicated in Fig. 3, and which is limited in its outwardmovement by a suitable lug or detent a5, which strikes against ashoulder on the fixed spoon. The iixed spoon has a longitudinal slot0,6, which is flanked by two recesses a8 to form a bearing for thejournal c of a link c, which passes through said slot. The pivoted spoonhas a T-shaped slot 0,7, through which works the shank of the link c, sothat the shoulders c2 of said link will ride upon the cams a9, lying onthe respective sides of the slot ai. The pitch of these cams is suchthat as the shoulders c2 of the link c ride up the surface thereof thetwo spoons will be drawn together, so that the socket ends @zand asthereof will embrace the ball-bearing b', which is attached by asuitable bracket h to the cutter-head B.

In order to provide an automatic adjustment of the spoons, I arrange astrong spiral spring (l, which is seated in the recess formed by theside walls of spoon d and bears against the shank of link c, therebytending to force the link into engagement with the cams et. The pressureof this spring is constant and serves to keep the sockets a2 a? of thespoons in operative engagement with the ball-bearing b. The pitch of thecam is such that however hard the shock of the pitman against theknife-head the link will not slide back on the cam and loosen the spoonson the ballbearing.

In assembling the parts link c is turned sidewise and dropped throughslot a and then turned so that the journal c engages the bearings as.The lower end of the link is then passed through the T-head of slot et?in spoon a', thereby compressing the spring d, which has been previouslyseated in the recess. In this position the jaws of the spoons, which aredistended, are brought over the ball-bearing b, when the pivoted spoonis swung on its pivot, and spring d forces the link forward, causing theshoulders c2 to engage and ride up the cams a". The sockets a2 and a3hug the ball-bearing b with just suicient force to insurev aneasy-working bearing, and any subsequent wear between the parts will beimmediately taken up by the springt?, forcing the link farther up thecams.

In order to remove the knife-head, the operator grasps the handle c3 andswings the link backward until the shoulders c2 lie in the T-head ofslot a7. Spoon a then drops away from the ball-bearing b', and theknife-head may be disengaged. XVhen the parts are to be assembled andthe bearing b is in position, it is only necessary to press the spoonstogether, when Vthe spring automatically looks and adjusts theconnection.

Having thus described my invention, what I claim isl. A pitmanconnection comprising a pair of cooperating spoons, means carried by theshank of one spoon, to lock said spoons in operative position, and aspring acting directly on said means to force said locking means intoengagement with the otherspoon.

2. A pitman connection comprising a pair of cooperating spoons, a linkcarried by the shank of one spoon to lock said spoons in operativeposition, and a spring located in a recess of one of said spoons andacting directly on said link to force said link into locking engagementwith the movable spoon.

3. A pitman connection, comprising coperating spoons, a spring-actuatedlink pivoted to one of said spoons, and a cam on the oth`er of saidspoons engaged by the link.

4. A pitman connection, comprisinga fixed spoon, a cooperating spoonpivoted thereto,v

a link carried by one of said spoons, a cam on the other of said spoons,and a spring carried by the fixed spoon to force said link into lockingengagement with the cam.

In testimony whereof I aIIx my signature in presence of two witnesses.

EDVARD A. JOHNSTON.

Vit-nesses:

B. R. BENJAMIN, WILLIAM WEBBER.

